Electromagnetic-wave shielding film, preparation method, and use thereof

Abstract

The present disclosure pertains to an electromagnetic-wave shielding film and a preparation method thereof. The electromagnetic-wave shielding film includes a first metal layer, an insulating layer, and a second metal layer. The first metal layer has two opposite surfaces. The insulating layer is disposed on one of the surfaces of the first metal layer. The second metal layer is disposed on the other surface of the first metal layer and contains nano metal particles and an binder. The electromagnetic-wave shielding film can be used in a printed circuit board, and shows a satisfactory electromagnetic wave shielding effect.

What is claimed is: 
     
       1. An electromagnetic-wave shielding film, comprising:
 a first metal layer, having two opposite surfaces, wherein the first metal layer consists essentially of silver, copper, aluminum, or any combination thereof; 
 an insulating layer, disposed on one of the surfaces of the first metal layer; and 
 a second metal layer, disposed on the other surface of the first metal layer, 
 wherein the second metal layer comprises nano metal particles and a binder; 
 wherein the binder is present in the second metal layer in an amount effective to enhance adhesion between the first and second metal layers, 
 and wherein the nano metal particles in the second metal layer are melted with each other to form a flexible metal nano-network; 
 wherein the nano metal particles in the second metal layer are aluminum, copper, silver, or any combination thereof; 
 wherein the second metal layer directly contacts the other surface of the first metal layer; and wherein the second metal layer has a thickness ranging from 100 nm to 1,500 nm. 
 
     
     
       2. The electromagnetic-wave shielding film according to  claim 1 , wherein the first metal layer has a thickness ranging from 10 nm to 300 nm, and the second metal layer has a thickness ranging from 250 nm to 1,000 nm. 
     
     
       3. The electromagnetic-wave shielding film according to  claim 1 , wherein the binder in the second metal layer is polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl butyral, polysiloxane, dihydrazide, acetylphenylhydrazine, phenylhydrazine, oxalyl-p-phenyldihydrazine, polyethylenimine, gum arabic, sodium polyphosphate, sodium lauryl sulfate, sodium lauryl sulfonate, dodecylamine, cetylamine, or any combination thereof. 
     
     
       4. The electromagnetic-wave shielding film according to  claim 1 , wherein in the second metal layer, based on 100 wt % of the total content of the nano metal particles and the binder, the total content of the nano metal particles is greater than 80 wt % and less than 100 wt %. 
     
     
       5. The electromagnetic-wave shielding film according to  claim 1 , wherein in the second metal laver, the nano metal particles have a size ranging from 3 nm to 200 nm. 
     
     
       6. A method for preparing the electromagnetic-wave shielding film according to  claim 1 , comprising:
 forming the first metal layer on the insulating layer; 
 applying a metal composition comprising the nano metal particles and the binder onto the first metal laver; and 
 performing a treatment process on the metal composition, the treatment process being selected from heat treatment, light treatment, or a combination thereof, such that a second metal layer formed on the first metal layer is obtained. 
 
     
     
       7. The method for preparing an electromagnetic-wave shielding film according to  claim 6 , wherein the metal composition is applied onto the first metal layer by coating, printing or spraying. 
     
     
       8. A printed circuit device, comprising: a printed circuit board and the electromagnetic-wave shielding film according to  claim 1  disposed on the printed circuit board.